Liquid oral compositions, such as a mouthwash, mouth rinse, oral spray, cough syrups and the like, typically contain flavor oils for imparting acceptable taste and mouthfeel characteristics. These compositions typically comprise a water, alcohol or water-alcohol carrier into which the flavor oils are dissolved or emulsified. The flavor oils normally include essential oils, such as peppermint oil, spearmint oil, eucalyptus oil, etc . . . as well as other flavor ingredients such as thymol, menthol, eucalyptol, methyl salicylate, and the like which are difficult to dissolve or emulsify in the aqueous/alcoholic carrier without the use of surfactants. Moreover, these flavor oils can impart turbidity and bitterness to the liquid oral composition.
U.S. Pat. No. 3,164,524 describes oral antiseptic compositions comprising an aqueous alcoholic solution containing menthol, methyl salicylate, thymol and eucalyptol. These compositions further comprise benzoic acid, boric acid and 2,2-thiobis-(4,6-dichlorophenol). Although having highly effective antiseptic properties, these compositions are known to have a relatively unpleasant bitter and biting taste.
U.S. Pat. No. 4,945,087 describes compositions containing thymol in which the unpleasant or harsh taste of thymol has been masked by the presence of a sugar alcohol and an effective amount of anethole. These compositions can also contain eucalyptol, menthol, benzoic acid, methyl salicylate and other optional ingredients.
U.S. Pat. No. 3,867,262 discloses a process for the preparation of terpeneless essential oils whereby the oil is distilled to remove non-volatile materials. The volatile components are adsorbed onto a solid alumina adsorbant which has been pre-treated with ethyl acetate to alter the relative affinity of the adsorbant for the terpenes and for the oxygenated components of the oil. The terpenes are separated from the desired constituents of the oil by elution of the adsorbant with a terpenephilic solvent.
U.S. Pat. No. 5,030,459 describes chewing gum compositions which contain a deterpenated and fractionated flavor oil for better flavor impact, greater sustained flavor release and improved taste. These compositions are solid chewing gum compositions and do not inlcude liquid oral compositions such as mouthwashes and cough syrups.
Because of the problems of turbidity and bitterness associated with the incorporation of flavor oils in liquid oral products, a need exists for flavor oils which have improved taste and a reduction or elimination of turbidity. It is an object of the present invention to provide liquid oral composition comprising flavor oil having improved taste and turbidity characteristics. It is a further object of this invention to provide liquid oral compositions, such as mouthwashes, sprays, rinses, cough syrups and the like, which have incorporated therein deterpenated and fractionated flavor oils. It is an even further object of the present invention to provide liquid oral compositions containing deterpenated and fractionated flavor oils which are non-bitter and non turbid. More specifically, it is an object of this invention to provide improved liquid oral compositions containing deterpenated and fractionated flavor oils wherein the monoterpenes and sesquiterpenses have been removed.